1. Statistics Vocab Notes
Unit 4

2. Mean
The average value of a data set, found by adding all values and dividing by the number of data points Example:
= 20
The Mean is 4

3. Median
The middle-most value of a data set; 50% of the data is less than this value, and 50% is greater than it Example: Put #’s in order 2,3,4,5,6 Median (Middle #) is 4

4. Range
The difference between the highest and lowest numbers in the data set. Example: 11, 12, 15, 17, 22, 23, – 11 = 18 The range is 18

5. Outlier
A data value that is much greater than or much less than the rest of the data in a data set.
Example:
164, 175, 126, 135, 55,159, 143

6. First Quartile
The value that identifies the lower 25% of the data; the median of the lower half of the data set; written as

7. Third Quartile
Value that identifies the upper 25% of the data; the median of the upper half of the data set; 75% of all data is less than this value; written as
Example:

8. Interquartile Range
The difference between the third and first quartiles; 50% of the data is contained within this range
Q Q3
Example: 11, 12, 15, 17, 22, 23, 29
Subtract Third Quartile - First Quartile = IQR
23 – 12 = 11
IQR = 11

9. Interquartile Range: 20 – 6 = 14
The numbers below represent the number of homeruns hit by players of the North Paulding baseball team.
2, 3, 5, 7, 8, 10, 14, 18, 19, 21, 25, 28
Q1 = 6
Q3 = 20
IQR = Q3 - Q1
Interquartile Range: 20 – 6 = 14

10. Interquartile Range: 20 – 6 = 14
Box and Whisker Plot
The numbers below represent the number of homeruns hit by players of the Hillgrove baseball team.
2, 3, 5, 7, 8, 10, 14, 18, 19, 21, 25, 28
Q1 = 6
Q3 = 20
Interquartile Range: 20 – 6 = 14 6 12 20

11. Box Plot
A plot showing the minimum, maximum, first quartile, median, and third quartile of a data set; the middle 50% of the data is indicated by a box. Example:

12. Dot Plot
A frequency plot that shows the number of times a response occurred in a data set, where each data value is represented by a dot. Example:

13. Histogram
A frequency plot that shows the number of times a response or range of responses occurred in a data set. Example: